Portable bicycle



FIG. 1 is a perspective view of a portable bicycle showing my new design.

FIG. 2 is a section view thereof taken along line 2--2 in FIG. 3.

FIG. 3 is a top plan view thereof.

FIG. 4 is a left side elevation view thereof.

FIG. 5 is a bottom plan view thereof.

FIG. 6 is a right side elevation view thereof.

FIG. 7 is a front elevation view thereof.

FIG. 8 is a rear elevation view thereof.

FIG. 9 is a left side elevation view thereof in folded condition. 

The ornamental design for a portable bicycle, as shown and described. 